The present invention relates to the connection of system units to a network.
In a computer network, the system units connected to the network are provided with respective identities (e.g., respective network addresses). It is important that conflicts between network identities are avoided as conflicts can lead to fault conditions occurring on the network.
The responsibility for allocating network identities can be achieved in many different ways, depending on the configuration of the network. In some systems, the network identities can be allocated centrally. In other examples, the network identities can be set in each of the system units connected to the network. In the present document, the term “system unit” is used generally to describe a component of the network that can communicate, either directly or indirectly, over the network.
A first system unit connectable to the network can be responsible for allocating respective network identities to a group of one or more second system units. Once the second system units have been allocated their respective network identities, they can then communicate over the network.
It has been determined that a problem can arise in such an arrangement if the first system unit is moved or is otherwise allocated to a group of third system units, where the group of second system units are still operating using their allocated network identities. This is because the first system unit can attempt to allocate to the group of third system units one or more of the network identities it allocated to the group of second system units. As a result, two system units could be allocated the same network identity and conflicts could occur.
The present invention seeks to address this.